Why do children play?

It's the end of the day, and you're exhausted, but it's sleepover night, and the kids are still running around in circles chasing their invisible tails. You may wonder: Why are they still playing? How do they still have energy?

You're not alone. Psychologists and philosophers have been pondering the reason children play for years (and probably had many sleepless nights, too). Philosopher Karl Groos argued that our penchant to play tag, climb trees and jump rope evolved by natural selection to teach us the physical and mental skills we need to survive and reproduce. So humans are hardwired to learn and have fun at the same time.

Studies on the reason children play have led to many different conclusions. The classical theories of playare largely philosophical and arose in the 19th and early 20th centuries [source: Saracho and Spodek]:

Modern theories of play emerged after 1920 and are supported by empirical research. They include the following:

As you've probably realized by now, there is no consensus on the reason children play — and this wasn't nearly an exhaustive list of theories.

One thing can be agreed upon, though: Play is beneficial and essential for a child's development. Through play, kids learn to make decisions, exercise self-control, respond to challenging situations and follow rules. Social play helps kids make friends, and it makes them happy [source: Gray].

But play's many benefits haven't stopped it from falling victim to our fast-paced and digitally preoccupied society.

As play declines, children have fewer opportunities to socialize and learn how to relate to the world around them. Some say they're becoming less empathetic and more narcissistic. For several decades, anxiety and depression rates in young people have risen, and suicide rates are more than twice what they were in the '50s. The prevalence of mental disorders has also increased [source: Gray]. Although there's no proof that diminishing play time solely causes these issues, it certainly has not helped.

One study showed that U.S. children in 2011 scored 85 percent lower on a creativity test than they did in 1984. Another showed that children in Britain were physically weaker than a decade earlier because of inactive lifestyles [sources: Gray, Campbell]. Unfortunately, telling your children to "go play outside" to get them out of your hair isn't such an easy sell these days. Not with all those smart phones, TV sets and video game consoles lying around the house.

But that doesn't mean that tech is necessarily the harbinger of play's death. Considering kids spend more time using digital media (more than six hours a day!) than doing any other activity besides sleeping, the future of play likely involves technological entertainment [source: Witherspoon and Manning]. Since it'd be impossible to pry controllers and keyboards from the hands of gamers everywhere, some researchers suggest active gaming as an alternative to inactive screen time.

Active games, like Wii Fit, martial-arts simulators and Gamercize steppers, have been popular for years. They require more energy and encourage kids to stay physically active while having fun. However, active gaming can't replace traditional free play, as studies show that they only moderately increase physical activity and decrease body mass index. Also, use of these games decreased over time, something that didn't happen with traditional video games [sources: Foley et al., Scharrer and Zeller]. Nevertheless, active gaming can be a stepping stone to a future with more unstructured outdoor play.

Additionally, there's a movement to bring back recess to American public schools. In 2006, 82 percent of elementary schoolchildren in the Chicago Public School system did not have recess. Thanks to grassroots campaigns organized by parents, all elementary schools had it restored by 2012 [source: COFI].

Companies such as Peaceful Playgrounds offer low-cost playground equipment such as multiuse circles and squares and grids featuring letters and numbers. These are designed to teach educational concepts and lessen the chances of playground mayhem, which may make recess more palatable to school principals. (In 2015, Peaceful Playgrounds was operating in more than 8,000 schools in America).

Inserting more play spaces in cities by integrating hopscotch into crosswalks or creating more play streets (neighborhood streets that close to traffic so kids can have more space to play) can make urban and suburban environments better places for children to play. These ideas may be part of the key to reviving interest among kids in free play.

Now, we just have to limit all that screen time and make them get off the couch.